Thread: V8 Coolant Hose temp ? Engine Smell?

This from over there

"PEM100990 - Cream is 88° With hard Spring (Designed for Diesel and V8 applications)

PEM101020 - Black or Cream is 82° With Hard Spring (Designed for a V8 and used as a stopgap with K4 engines)

PEL500110 - Grey is 82° With Light Spring (K4 engines)

The spring referred to is the pressure relief setting. the car K4 engine has a lighter spring because the volume flow is much smaller than the V8 or diesel engines.

the 88C is 192F and the 82C is 180F the listed temperature at full opening."


the second is interesting--

Originally Posted by diesel

I'm actually ordering a PEL500110 stat now from the UK. From what I have read it lowers the overall temps a few degrees and remains at a steady temp rather than fluctuating.

See here.

FYI I have 56D engine.

M

Thanks for this, appears it's made for the 1.8 K Series (helped with the Head Gasket issues I have read!) and the TD5 engine.

Can this be used on the 4.0l V8?

found this on an MG Rover forum,,,


As I mentioned in my first post, the difference between any of these in real world terms is negligible and the only thing you may notice is a slight change to heater performance.

When the engine is being pushed and cooling becomes an issue, they will all be operating above their set temperatures and be wide open. The pressure spring side of things just makes a slight change to the engine speed at which the stat will open regardless of temperature.
Dr Rik


any techy people care to comment?

Originally Posted by Pedro_The_Swift

The pressure spring side of things just makes a slight change to the engine speed at which the stat will open regardless of temperature.

I believe this statement that you quote from the MG forum is just a little incorrect. The thermostat bypass and the spring weight has to do with how the system behaves when cold. The D2 (and I guess other land rover cooling systems) will bypass the radiator when cold and most of the coolant flows through the heater core/matrix instead. This allows the engine and passenger compartment to come up to temperature more quickly. The bypass spring allow for coolant to flow through the radiator instead when revs increase or for other reasons that would cause the coolant pressure to increase. With the softer spring, it's more likely to bypass the heater-core-only circuit, and pump coolant through the radiator too. The only downfall of this is it might take a little longer for the heater to feel hot on a cold day.

When the engine is up to full operating temperature, the main portion of the thermostat is open, and the bypass and the spring are completely out of the equation.

Thanks jafir,,

I asked for a price of a
PEM101020
from a MG Rover spares shop(in OZ) and was quoted $90--

Spoke with my Father in the UK today to get a price and also to Ayres Auto Sydney Land Rover.

Both people I trust said leave the standard one in the car!.

Below is the note from the LR guy in Sydney. Which is also what my father said.
=======================
Rob
It is important that the correct temperature thermostat is always fitted in your car, not a cooler one!
With a cooler thermostat the engine management system thinks the engine hasn’t reached normal operating temperature yet and will inject more fuel.
The engine is designed to run at a specific temperature and that is usually as hot as possible without overheating. This is where Rover V8 engines are the most efficient.
What determines whether the car will overheat or not in hot weather is the size and cleanliness of the radiator (internally & externally) and proper functioning of the viscous coupling in the fan. The coolant is directed through the radiator as needed by the thermostat to maintain exact engine temperature, probably about 95 degrees in your case.
To fit a cooler thermostat will promote poor economy and increased engine wear.
===============

I was also told that the 95c Thermostats are designed to get the engine up to temp quite quick and keep the temp stable.

Cooler Thermostats will give heavy fluctuation in when driving and The head gaskets dont like this much!.

I think I will stick to taking care of he cooling system as LR designed it.

Originally Posted by Robgw

With a cooler thermostat the engine management system thinks the engine hasn’t reached normal operating temperature yet and will inject more fuel.

The only colder thermostats available still allow the engine to run in closed loop. Running at the factory specified temp will probably allow the system to run a little bit leaner and reduce emissions, but I'll bet you'd have a hard time seeing the difference when it comes time to pay for fuel.

Now if you were to do the thermostat mod listed here: Inline Thermostat - LAND ROVER CLUB V.I. then you could pick whatever thermostat you wanted, and if you pick something too cool, you'd run the risk of never getting to closed loop operation, and the engine would run way too rich.

Originally Posted by Robgw

Cooler Thermostats will give heavy fluctuation in when driving and The head gaskets dont like this much!.

There is a no reason a slightly cooler thermostat would cause fluctuations. And having the temps lower would probably be BETTER for the head gaskets.

A can of worms here indeed!

Seems lots of evidence either way.

I think i will be sticking to what I have and keeping the cooling system well maintained, after all the car has not had an issue in 11 years.

A system flush once a year won't hurt.

Rob